California’s big battery experiment: a turning point for energy storage?

The world's largest lithium-ion battery installed after the Aliso Canyon gas blowout has become a test case for the grid storage industry

On a paved expanse next to an electrical substation in Escondido, 30 miles north of downtown San Diego, sits a row of huge silver boxes. The site resembles a barracks, but instead of soldiers, the 24 containers house racks of battery packs.

This is the largest lithium-ion battery in the world, according to its developers. When the local grid needs more power, these batteries deliver, almost instantaneously. They hold up to 30 megawatts fully charged - roughly equivalent to powering 20,000 homes - and can sustain that level for up to four hours.